.main
  background-color: #000;
  height 100%
  padding 0 20px
header
  text-align center
  color #ffffff
  font-size 48px
  height 10%
body
  position relative
  display flex
  justify-content space-around
  align-items center
.exhibit,.explain
  height 500px
  width 500px
  border 1px solid #cccccc
  border-top none
  border-bottom none
  display flex
  justify-content center
  align-items center
.taiji
  width 200px
  height 200px
  border 1px solid #000
  background-color #fff
  position relative
  overflow hidden
  display flex
  flex-direction column
  align-items center
  .rightBg
    width 50%
    height 100%
    position absolute
    right 0
    background-color #000